The Rules
by JeVeuxReves
Summary: The rules for being Hamada brothers are always growing and changing, but it's not following them that's fun: it's creating them.
1. Orphan

Cass Hamada was still in shock. When she had answered the cafe's phone, she had expected someone to order a dozen donuts, not tell her that her brother and sister-in-law had died in a car accident and their youngest son hadn't woken up.

Now, she sat in the ICU beside a comatose toddler while a nurse patched up an oddly silent seven year old. Tadashi had reportedly flatly refused treatment until Hiro had been looked after, and no one could convince him to leave his brother's side. He had kicked up enough of a tantrum to get his way, and now he sat on the end of the bed, littered with bandages, staring blankly at the wall while a nurse stitched a cut over his eyebrow.

Tadashi, as Cass understood it, had escaped with the fewest injuries, but the police had found him in the backseat of the car, sitting behind his dead parents and holding his unconscious brother. No one knew what damage that had done to his mind, and a psych evaluation was going to have to wait. "You're all done. You handled that like a champ, you know."

The seven year old shrugged. "I got off easy. This is nothing." He glanced at the nurse, remembering his manners. "Thank you for your help." The he looked back at his brother, thin face set in stubborn lines.

The nurse looked taken aback, but she nodded and forced a smile. "I'll see if we have the results back for Hiro." She left them alone in the room, and Tadashi pulled himself up and crossed his legs on the end of the bed. "Aunt Cass."

She looked up at the oddly serious boy, as the doctor stepped into the room. "Ms. Hamada? Could I speak to you outside, please?" The doctor looked pointedly at Tadashi's back.

"No." Tadashi answered for her, his voice harsh. "Whatever you have to say to Aunt Cass, you can say in front of me too."

"Tadashi... Sweetheart, maybe it's better if I talk to the doctors."

"Hiro's comatose." Tadashi rattled off angrily. "Clearly because of head trauma. Most likely, there's swelling in his brain and he'll wake up when the swelling goes down. The trauma could have caused brain death, but at this point, it's too early to make that call. The longer Hiro is comatose, the higher the likelihood that he will experience brain damage. Did I miss anything?" He demanded, trying to stand up and swaying on his feet. Cass reached out to steady him, but he slipped out of her reach, holding onto the bed rail to keep himself upright.

"How did you...?"

"I like reading medical journals." Tadashi snapped dismissively. "Am I wrong?"

"N... No." The doctor admitted, staring at him in surprise. Cass, who was more or less used to the way her nephews seemed to know and understand things way beyond what children their age should be able to, was less blindsided by the boy's intelligence, but it still ached to hear him say those words about his brother. "Ms. Hamada, it's important that you prepare yourself for the possibility that Hiro might not wake up, and make a decision on what you would like to do in the event that he doesn't."

Cass nodded tearfully, and this time when she reached for Tadashi, he let her pull him into a hug, wrapping his skinny arms around her waist. "He's going to wake up." He murmured, certainty in his voice.

Hours later, Cass was in the elevator, having gone to get something for dinner for the two of them. Tadashi had elected to stay behind, unwilling to leave his brother's side for even a moment. She had been told that the boy had gone into shock because he couldn't deal with the trauma of what he'd seen, and that was why he had been so calm about this entire thing. Apparently, he had yet to break down, and no one had seen him shed so much as a single tear. She had no idea how to deal with this kind of stoicism from a child when she herself was barely holding together. She headed towards the room, but the sounds of Tadashi's voice made her stop just in the doorway.

The child was sitting at the edge of his chair, his brother's hand cradled in both of his. "They don't think you're going to wake up, but I know better. You're _way_ too boneheaded to let something like this get you down, right Hiro?" He seemed to be waiting for a response, and when he didn't get one, he shook the hand he held gently. "C'mon, you have to wake up. Rule # 1: Hamadas stick together. You're my little brother, and you're all I have _left_. Hiro, please." Then came the tears: One rolled slowly down that bruised cheek, then another, and then Tadashi pitched forward, burying his face in the blanket at his brother's side and sobbing into the mattress, holding onto that tiny hand like it was his only lifeline.

Cass left them alone together and sank into a chair in the waiting room, her face in her hands, giving into her own grief where Tadashi wouldn't see. Years later, she would look back on that day and realize that it wasn't shock to blame for Tadashi's manner. The accident changed him, forced him to grow up before his time.

It was just past dawn when the blankets moved under Tadashi's arms, stirring him from his sleep. "'Dashi?"

The seven year old sat straight up, staring into the familiar brown eyes. "Hiro?" He laughed once in disbelief, and then grinned broadly, hugging his baby brother. "Aunt Cass! _Aunt Cass!" _

Cass ran into the room to see Hiro, blinking in confusion, crushed in his brother's arms, and then with the articulation that no three year old was supposed to have, he asked. "Aunt Cass, what happened and why is Tadashi crushing me?"

Hiro cried when they told him, clutching his brother and wailing into his shirt, and Tadashi hugged him and promised over and over again that they were going to be okay. They were going to get through this, because they still had each other, and he and Aunt Cass were going to take good care of Hiro.

Cass knew that it wasn't going to be easy, but looking at the brothers, she knew that things were going to be okay.


	2. Genius

**Author's Note: This story is NOT chronological. Tadashi and Hiro's ages are going to be constantly fluctuating, but I'll usually let you know how old they are in each particular chapter. Reviews are love. **

Tadashi Hamada was lying on his stomach on the linoleum floor, his math textbook propped open against the leg of one of the kitchen chairs, a piece of paper underneath his hand, and finding it _very difficult_ to focus on long division.

The chubby, five year old fingers that were buried in his hair tugged painfully at his scalp, and Tadashi snapped the lead on his mechanical pencil with the resultant jerk of his hand. "Ow! Hiro, stop that!"

"I'm _bored!_" Hiro complained. "Dashi, what are you doing anyway?"

"My homework. Fifth grade is harder than kindergarten." Tadashi snapped.

"I hope so." Hiro replied with some feeling. "I already _know_ how to read and count to 100."

"Well unless you know long division, be quiet!" Hiro stopped talking, looking at Tadashi's paper for several seconds, then turning his attention to the textbook. The ten year old would have preferred it if his brother would also stop using him as a chair, but Hiro's silence was a small victory that he was willing to accept. He turned his attention back to the problem: 7810/2. He worked his way through the problem carefully, and Hiro spoke as he completed his answer.

"3,905."

"I told you to be quiet!" He repeated angrily.

"No, you said to be quiet unless I know long division. I know it, so I don't have to be quiet." Hiro corrected primly.

A less patient big brother would have hit him, and Tadashi hadn't quite ruled it out as an option. "Bonehead. You can't read my answer and pretend you know it."

"I _do_ know it!"

"Prove it then! The next one is 5960/4. What's the answer?" Hiro shut up, and Tadashi smiled smugly as he copied out the problem, thinking that if Hiro admitted to reading his answer, he would try to teach his little brother how to do it properly.

"1,490." Hiro announced.

"Sure it is." Tadashi replied, rolling his eyes and solving the problem. He stared at the numbers, carefully printed out in his own, neat handwriting. Now it was Hiro's turn to be smug.

"Told you."

"How did you...?"

"I _divided _it." Hiro said, as though the answer was obvious. "The next one is 192, by the way."

"Stop that!" Tadashi sat up abruptly, and Hiro wrapped his toothpick arms around his brother's neck to keep himself upright. He glanced at the next problem, calculated the answer in his head, and upon discovering that Hiro was correct again, he slipped his arms under the legs clamped around his waist and give Hiro a piggyback ride downstairs and into the kitchen of the cafe. He ducked around the bar and set Hiro down on one of the stools, looking around for his aunt.

"Dashi? Am I in trouble?

"I don't know. No." Tadashi replied distractedly. He spotted her at a table near the door, loading empty dishes onto a tray. "_Stay here, Hiro_." He said sternly, then ducked across the room.

"Oh, Tadashi, are you done with your homework already?" Cass asked, looking around until she spotted Hiro sulking on the barstool. Tadashi grimaced. He knew that Aunt Cass didn't mind if he and Hiro came down to the cafe, but whenever they did, she would be busy trying to help her customers _and_ keep an eye on her nephews. Tadashi didn't like to worry her, so the two usually stayed upstairs during the afternoons. Today was a rare exception.

"No, I've still got- here, let me." He grabbed the rag she held and quickly wiped the table down. "I was working on my homework, and then _Hiro_ started doing it."

Aunt Cass laughed. "Two more chai teas? Coming right up!" Tadashi smiled apologetically at the customers before rushing after his aunt. "Tadashi, can you run these dishes to the sink?"

"Sure." He grabbed the tray and hurried into the kitchen, washing the cups efficiently before going back to his aunt's side. "But when Hiro was reading my math book-"

Aunt Cass ruffled his hair and leaned down to press a kiss to the top of his head. "Sweetie, I know that Hiro can be energetic, but can't you let him watch you do your homework? The cafe is just too busy for me to keep an eye on him today."

"That's the thing, Aunt Cass, he was getting the answers right!" Tadashi said quickly. _That_ stopped her. She looked at Hiro, who was shooting her and Tadashi guilty looks, as though he had been caught doing something wrong. She dropped the chai teas off and then went to sit next to her nephew. "Hiro, what's 4128/4?" Tadashi asked.

Hiro bit his lip, exhaling through the gap in his front teeth as he thought about it. "1,032." He said finally.

"Honey, did you figure that out in your head?" Cass asked, staring at him in disbelief.

"I'm sorry." Hiro mumbled.

Cass pulled him into a tight hug. "Don't be sorry. This means you're _smart_, Hiro!"

They found out later that Hiro was more than smart: he was a genius. Aunt Cass was unbelievably proud of him, and all of her customers knew it.

Tadashi didn't know how he felt about it, and so he had taken to avoiding his brother. He sat on his bed, a book propped open on his lap, trying to figure it out. His parents had been smart, and Hiro was a genius, but he wasn't. He knew he was smart too – he had good grades, and he understood the lessons his teacher taught, but Hiro was a _genius_, and he was just... average. Did Aunt Cass think less of him because of that? Would Mom and Dad?

A sudden weight at the end of his bed made him scowl, and the look on Hiro's face when he saw the look on Tadashi's made him feel like a jerk. "Dashi?"

"What's up, Bonehead?"

"Hey! I'm not a bonehead! I'm a genius!" Hiro protested, making Tadashi frown again. "Dashi, do you still like me even though I'm smart?"

It was official. He was the worst big brother in the world. "Yeah, Hiro. I still like you."

"Then why don't you play with me anymore?"

Make that the worst brother in the _universe_. He flopped back onto his pillows and Hiro settled into his favorite spot, sitting cross-legged across his brother's waist. "It's not easy to realize that your bonehead baby brother is smarter than you." Tadashi explained guiltily. "I'm supposed to be the smart one."

"You _are _smart." Hiro replied. "You know tons of stuff, and you taught me. I knew how to read before I started school because you taught me. And you know how to fix the toaster and you built your computer. Of course you're smart."

Tadashi smiled despite himself. "I built a great computer, didn't I?" He pulled his brother into a hug. "Thanks, Bonehead."

"Mom and Dad would think you're smart too." Hiro's voice was muffled against Tadashi's shoulder, but it was _exactly_ what he needed to hear.

Tadashi was up late that night, unable to sleep. Finally, he sat up and looked at the cocoon of blankets that was his brother. "Hiro? Are you awake?" He received no answer, and he twisted his fingers together staring at his hands. "Mom and Dad would be ashamed of me for the way I've been acting. I got jealous, and I let that mess things up. But that's _my_ problem, not yours, and it's not your fault either. Mom and Dad are gone, and that means that it's my job to be proud of you since they aren't here to be. I'm your big brother, and that means I'll always be there to look out for you and protect you and -this is important, okay? I will always, _always_ like you, _especially_ because you're smart. Rule # 2: _Nothing_ comes between us. I love you, Bonehead." He settled back down, pulling his blankets up around his chin and closed his eyes.

"I love you too, Dashi."


	3. Remember

**Author's Note: The story of the baseball cap, because it needs a story. A bit angsty, mostly fluff. **

Hiro and Tadashi stood in the center of the garage, two very small figures amongst a cluttered mess. "We'd better get started." Tadashi said finally.

"How are we going to get this done?" Hiro asked.

Tadashi picked up a box and set it on the ground, settling beside it and pulling off the tape that held it closed. "By doing one thing at a time."

It took _hours_, but every thing in the garage was examined, considered, and occasionally debated over before it was sorted into one of two ever growing piles: things to keep, and things to get rid of.

The 'going' pile was then packed into boxes and stacked neatly in a corner. It was in that pile that Tadashi found it. He picked up the hat and dusted it off carefully with his sleeve. "This was Dad's."

Hiro came to his side, looking at the San Fransokyo Ninjas logo on the front. "I don't remember it." He admitted in a very small voice. The nine year old wrapped an arm around his shoulders, pulling him into a hug.

After that, Tadashi talked as they worked, telling Hiro about the way their parents had turned Sunday mornings into a tradition of family breakfast. The would maneuver around the kitchen (and each other) without so much as a single misstep, and Mom would sing and Dad would filch pieces of bacon when he thought she wasn't looking, and they would task Tadashi with setting the table. He talked about how he would climb onto the counter to get the plates because he was too small to reach, and Dad would let him sit on his shoulders so he could grab them. He talked about how Mom was short and thin and would switch between English and Japanese when she was angry, and how Dad was tall and broad and about the way he always pushed his glasses up his long nose. He set their father's hat on his own head and told Hiro about the game their parents had taken them to, how the Ninjas had lost spectacularly to the other team, and when Tadashi questioned why his father bought the hat, Dad had explained that you don't give up on something just because it's not always the best.

Hiro pelted him with questions, and Tadashi answered the ones he could and made a mental note to ask Aunt Cass about the ones he couldn't, and eventually, the two of them stood in a clean garage, with everything they were keeping placed neatly away on shelves and tucked into drawers.

"I think we're done." Hiro said.

'Yeah, but what are we going to do about this grocery cart?" Tadashi asked, adding _where did you even get this? _to his growing list of questions for his aunt.

Hiro walked around in, his brow furrowed while he considered. "You know... with a few thrusters, this thing could be a hover cart."

"_Thrusters?" _Tadashi was scandalized. "Electro mag suspension would be _so _much better!"

"Or an anti-gravity field." Hiro suggested. "Rule # 112: If it doesn't fly, it should."

Tadashi grinned.


	4. Hustle

**Author's Note: Thank you to all my reviewers! You guys are all the absolute best! This chapter is just for fun, brother love, and because my headcanon is that Tadashi knows WAY more than he should and tries to shoulder the responsibility for pretty much everything.**

Hiro wasn't _quite_ ready to go home yet. Ever since Tadashi had started at SFIT, he had been gone well into the evenings, and their bedroom seemed too big and empty to spend much time in it. The four or five projects they had in the garage had taken a backseat to Tadashi's schoolwork, and his classes must have been _hard_, because he was exhausted when he came home every day.

Hiro ducked into a restaurant, figuring he would kill some time before he went home, maybe get a bit of homework done. He sat down with a cup of tea and opened his trig textbook. He was halfway done with the assignment when someone called his name. "Hamada!" He looked up to see one of the employees looking at something behind him. "Take a break."

"Okay." The voice made him turn around to see his brother, wearing the restaurant's uniform.

"Tadashi?"

Hiro had worn the 'caught in the act' expression often enough to recognize it on his brother's face. "Oh man." Tadashi ran a hand over his face and slid into the booth opposite his brother. "You _can't_ tell Aunt Cass."

"You're supposed to be in class." Hiro said. He didn't _meant_ to sound accusing, but Tadashi looked guilty and he thought maybe he'd missed the mark.

"I didn't get the scholarship. Apparently, there's this showcase thing, and it went to someone else." Tadashi explained. "Aunt Cass would never say anything, but the cafe hasn't really been doing well lately, and the bill for my wrist was _way_ more expensive than I'd realized. You know Aunt Cass. She'd pay to put me through college, and she would bankrupt herself and pretend like everything is okay. I can't let her do that. So I told her I got the scholarship and I got a job instead. I can't ask her to pay tuition, but in a year, I'll have made enough to pay for a semester, and when I turn eighteen, I can apply for student loans and Aunt Cass never has to know. So you can't tell her, okay? Rule # 378: Hamada brothers don't narc on each other."

Usually, it was Hiro begging _Tadashi_ not to tell Aunt Cass. "I won't tell her." He hung out with his brother for the rest of his break and left the restaurant feeling guilty. He had never even considered that Tadashi would be unable to go to college. He made the short walk home lost in thought. For as long as he could remember, his older brother had been talking about being a robotics major at SFIT. He had read up on the school, he even had the website _bookmarked_ on his computer. But he couldn't go, and even when he _did_, he would be paying off student loans for years. It didn't seem fair. There had to be something that he could do to help, but how could an eleven year old get the kind of money tuition required? Donating his ten dollar a week allowance from Aunt Cass wouldn't exactly help much.

But what if... what if there was a way to multiply that ten dollars? Turn it into twenty... forty, eighty, one-sixty, three-twenty...? Hiro grinned. Tadashi had always looked out for his little brother. Hiro had no qualms about returning the favor.

That was how Hiro and Tadashi end up here, huddled together on a fire escape at one in the morning, shivering against the January chill. San Fransokyo has a very mild climate this close to the equator, but a light hoodie and a cardigan aren't enough to combat temperatures dropping below forty. "I c...can't _believe_ you!" Tadashi whispers harshly around chattering teeth.

"It's not like I p...p...planned this!" Hiro hisses back, snuggling closer to his brother's body heat. "How long until you think the cops leave?"

"I d...don't know! Run-ins with the police are _your _area of expertise!" Tadashi snaps, and Hiro winces at the accusation and doesn't say anything more.

It had been two weeks ago that Tadashi had been convinced something was wrong. He sat in front of the computer, frowning at the screen, holding his phone to his ear. "... Right, that matches the balance I have here. But there's a two hundred dollar deposit to my account that I didn't make."

"Are you sure?" The representative from his bank asked. "My notes say that it was desposited in cash at a branch last week, into the account for Tadashi Hamada."

"It must be another Tadashi." Tadashi said. "I never put that money in."

"No, it wasn't you who desposited the funds. I have here that it was a... Hiro Hamada?"

_Hiro?_ "Oh... okay. Thanks." He hung up his phone and turned to look at Hiro, sitting on his bed and failing to look casual. "Where did _you_ get two hundred dollars?"

Hiro sighed. "I've been doing stuff for people at school. You know, speeding hard drives up, removing viruses from computers, building the apps they want, helping with homework..."

"By 'helping,' do you mean 'doing?'" Tadashi asked sternly. Hiro bit his lip. "Unbelievable. Do you know how much trouble you can get into if you get caught? And why are you putting it into _my_ bank account?"

"I didn't want you to have to take out student loans." Hiro admitted. "And I said I wouldn't tell Aunt Cass, so my options are kind of limited."

Tadashi was touched, admittedly, but... "Hiro, I'm not taking your money."

"It's not up for discussion, Tadashi." Hiro replied shortly. "You've been helping me out my entire life. I'm doing this, and I'm not asking permission, so just say 'thanks Hiro' and drop it."

Tadashi found himself in the unique position of having heard an 'end of discussion' moment from his little brother, and he stared at him. "... Thanks, Hiro." He knew he would never use a penny of Hiro's money. It just wasn't going to happen, but if Hiro was going to be this stubborn about it... he supposed he could open separate account, and if, when Hiro graduated in a few years, _he_ wanted to go to college, that money would be waiting for him.

Tadashi was _almost_ asleep when he heard Hiro moving. "What are you doing Knucklehead?" He asked, opening his eyes to see Hiro finish putting his shoes on and grab his phone from his bedside table. He sat up. "Where are you going?"

"Can't sleep." Hiro replied, zipping up his hoodie. "I'm just going down to the garage. I might as well get some work in."

Tadashi yawned. "Don't stay up too late." He settled down, pulling his blanket back up over his shoulders as Hiro headed downstairs, being quiet so he didn't wake Aunt Cass. It only took him a few minutes until he was once again on the verge of falling asleep.

Wait.

Hiro had grabbed his phone off his table to go down to the garage, where the phone's signal interfered with the robotics. Which was why they _never_ took their phones into the garage. "Son of a -!" Tadashi was out of bed in an instant, lying on the floor on his stomach, groping under his bed for his other sneaker and _where_ was his jacket?!

After what felt like too long, he was running out the door after his brother, pulling up the app on his phone that tracked the GPS signal on Hiro's. How had he gotten _that far_ this quickly? He maneuvered his way through rapidly emptying streets, his nose to his phone, and when he looked up, he wasn't sure when he had left the... nicer... parts of San Fransokyo behind. He followed the GPS down dark, empty streets, and finally ducked down an alleyway in the industrial district. He could hear low voices, and the clash of metal on metal, and his pace quickened without him realizing it.

He turned around a building and ended up in the middle of a small crowd. There were at least thirty people crammed in this tiny alleyway, and Tadashi stretched onto his toes, trying to see what they were gathered around. There was a collective groan, and he heard a very familiar voice. "No! I didn't know it could... I've never fought before." The word _fought_ acted like a catalyst. He shouldered roughly through the crowd towards the sound of his brother's voice, and found Hiro sitting on the ground, a controller in his lap. "Can I go again? I've got... eighty?" He held up the bills, and Tadashi was going to _slaughter_ him, but then the money changed hands and the fight started anew.

The twisted scrap of metal reformed, and moved forward again. It moved around the other bot, going in clumsily, pulling back at the very last second, and Tadashi looked at his brother, really _looked_ at him. Because they had never played a video game together that Hiro didn't inevitably win, and Hiro's shoulders were relaxed, and there was none of that frantic button pushing on his controller that was a sure sign that Hiro thought he might lose. Then he looked at the bot, which had landed a weak hit, then dropped back, circling. It looked shoddy at first glance, but the actuators were _perfect_ and the motion was smooth and even. His brother toyed with his opponent for a long moment, and then the fight was abruptly over.

Hiro was all blithe smiles and innocent surprise as he collected the entire pot. Tadashi decided to call his bluff. "Don't let him fool you." He announced loudly to the man Hiro had beat. "You've been hustled."

Hiro's head whipped around, and the color drained from his face. "Hey Tadashi."

"What do you mean, hustled?" The man asked, glaring at Hiro.

Tadashi had already moved on, glaring at his brother. "What were you _thinking_, Hiro? I can't-" He fell silent abruptly when he heard the sirens. The crowd scattered, and Hiro seized his hand, dragging him down sidestreets and back alleys. Tadashi followed him, but continued his tirade. "What is _wrong_ with you?! You know bot fighting is illegal, and what happens when you hustle the wrong guy? You could end up in the hospital or _dead!_ There is no excuse for this!"

"Can't you lecture me when we get home?!" Hiro cried. "You're gonna get us caught!"

Tadashi stopped, grabbing Hiro by the hood to stop him as well, and reached up to pull a fire escape down. "Climb. _Quick_." Hiro obeyed, and Tadashi followed him, urging him on until they were several stories up.

Hiro is all but in his lap when the sound of sirens _finally_ fades, pressed tight against Tadashi's side, with his brother's arm draped around his shoulders. Tadashi's nose is red and his lips are blue and he's _freezing_. Hiro, sucking up all his body heat, seems perfectly okay. "I think they're gone."

"Finally." Tadashi starts down the fire escape first, and then, at two thirty in the morning, they're on their way home. "It's a good thing Aunt Cass didn't wake up and realize we weren't home." Tadashi says, glaring at his brother.

"Yeah... about that. Don't tell Aunt Cass, okay?"

"Oh, I'm _definitely_ telling Aunt Cass." Tadashi assures him. "You're lucky I'm not telling the _police!_"

"What!?" Hiro yelps. "What about Rule 378? Hamada brothers don't narc."

"This is against the _law_, Hiro!" Tadashi replies. Hiro stares sullenly at his brother's back, before a realization hits him and he grins.

"So Tadashi, how are your classes going?"

"You _wouldn't_." Tadashi accuses.

"I would."

"You sneaky little... I _knew_ I was going to regret telling you!"


	5. Pride

**Author's Note: This chapter is so Tadashi centric that it's RIDICULOUS, but I love the character. I wrote it from Cass's POV, which was REALLY fun to write, and I hope it's in character. Let me know how I did! Thanks as always to you lovely people who reviewed, faved, and followed!**

Cass worries about her nephew, maybe even more than his brother. Tadashi never brings it up, and she takes her cue from him, but she's pretty sure that it isn't elves sneaking into the kitchen and washing dishes (because she's very sure _she_ hasn't cleaned that many) and if Tadashi is in the cafe eating lunch and she has to go to the back for something, well, the tables aren't wiping _themselves_ down.

She's careful not to ask him for help, and she can only assume she's equally careful, because she never sees him give it. He's thirteen now, and teenagers are supposed to be loud and unruly and stubborn, but even as he grows like a weed and eats twice as much as he used to, he doesn't change. He's still calm and polite and mild mannered. He's still soft – and very well- spoken, and she begins to really pay attention, because she's sure that many of his expressions don't belong on a thirteen year old face. Sometimes, he looks so world weary she has to laugh. Then he looks at her guiltily, like he knows what she's thinking, and the joke isn't funny anymore.

She's tried to let them be kids, but Hiro has always been a handful, no matter how you slice it, and she's afraid that she's depended too much on Tadashi's innate calm, his ability to tease and cajole Hiro out of whatever insane idea he has without ever once stifling his brother's intelligence and creativity. She's afraid that she's made him grow up too fast. He never complains, but then, he never would.

She thinks she treats Tadashi more like a very small adult, rather than the boy he is. She doesn't talk to him like he's a child. She doesn't share everything, because he doesn't need to know that her car is on the verge of breaking down and she's going to have to clip _a lot_ of coupons this month to be able to afford groceries, because the cafe isn't doing very well, but she doesn't talk to him like a child, either.

It doesn't help that, the more he grows, the more his expressions and features remind her of his father, the big brother that she still misses. When his voice changes, he even _sounds_ like his father, and she keeps calling him by the wrong name and he tries to hide the sadness in the smile he gives her, but he's not fooling anyone.

It's very late when he offers her a glimpse into the fears he still carries, what weighs heavily on that young, brilliant mind of his. It's the first day of a new school year tomorrow, and Tadashi will be starting as a freshman in high school, having skipped the eighth grade. Hiro had skipped second and third, and would be starting fourth.

She had thought they were both asleep, but when she enters the kitchen, she finds Tadashi seated at the table, contemplating the cup of tea his fingers are curled around. She should send him to bed, really, but instead she cuts two slices of coffee cake and sits across from him. "Do you want to talk about it?" She asks, and she _hopes_ the answer will be 'yes' but expects it to be 'no' because she's never seen Tadashi talk about his problems _ever_. She thinks it's because he thinks it will burden someone else, and he looks at her face, quick chocolate eyes reading her very thoughts, and offers a wry smile. It makes him look much older than he is.

"Mom and Dad would be so proud of him." He says in that soothing tenor she's still not used to.

"They would be proud of both of you." She corrects, and his mouth smiles, but the rest of him doesn't.

"But Hiro especially. I mean, he's a genius."

"So are you." She said, and his face is skeptical and she's honestly surprised, because she thought he _knew_. "You really don't realize that you're smarter than just any thirteen year old? Even I can't understand half of what you and Hiro talk about."

He stares at her, and she can tell that he wants to hope that she's' telling the truth, but can't quite let himself. "But Mom and Dad were so smart, and Hiro skipped two grades."

"Sweetie, you were _seven_ when the accident happened, and your mother was a biochemist and your father was an engineering physicist. Of course they seemed smarter than you. And just because Hiro is a genius doesn't mean you're not. You were reading medical journals when other kids your age were reading children's books."

"I hadn't considered that." Tadashi says seriously, and he links his fingers together in front of his mouth and for a moment, the resemblance steals her breath, makes something in her chest ache. Then he drops his hands to the table, leans forward on his elbows, and the spell is broken. "Aunt Cass?" He asks, looking concerned.

"Have I ever told you how much you're like your dad?"

His gaze returns to his tea, and he's not _crying_, exactly, but his eyes are a little misty. "I miss them." He says, quietly, like it's some kind of big secret. Then he looks guilty. "Sometimes... I wonder what our lives would be like if they were still alive. Not that you're not great. I like living here, and I know Hiro does too."

"Oh Sweetie, you don't have to explain. I know how you feel, and I know your mom and dad didn't want to leave you. You should have heard the way he raved about the two of you, _you _in particular." She drops her voice as low as she can in a terrible impression of her brother. "'You should see this, Cass! We wouldn't let Tadashi have the remote so he _built his own!_ My boy is going to be the next Tesla!'"

Tadashi laughs. "The remote! I forgot I did that. Mom and Dad got so _mad!" _

"They would be watching the news, and you would switch the channel to some big robotics convention."

"The International Conference on Robotics and Automation. SFIT had an exposition that I wanted to see." Tadashi remembers. "I'm going to go there someday, and I'm going to built something amazing."

"Oh yeah? Any brilliant ideas?" She asks, half teasing.

"Do you know how many people die each year because of medical mistakes? Or because they go to a doctor for one thing and get treated for something that they don't have because they were misdiagnosed? I think everyone should be satisfied with their care." He muses, his gaze far away. "Tesla once said 'The desire that guides me in all I do is the desire to harness the forces of nature to the service of mankind.' I want to make something to help people. People who are sick or hurt or scared of hospitals like Hiro is."

Hiro _is_ scared of hospitals, despite spending what Cass is pretty sure is more than a normal amount of time in them. They're brilliant, her nephews, but sometimes their ideas run away with them. "That's..." Cass doesn't have to words to describe what that is. Tadashi, her sweet, _amazing_ nephew, wants to revolutionize the world at thirteen. "You're going to do amazing things." The words don't convey everything she wants to say, but she thinks he gets it, because he grins, and it's dazzling. _He's_ dazzling, all shiny idealism and unassuming brilliance, wrapped up together with pure, untainted kindness, and she honestly doesn't know what she would do without him.

"I hope so." He says fervently, and the words are simple, but she knows what he's trying to say.

The first day of school is always hectic, and she's always frazzled, running around and making sure that they have everything they'll need to be successful, and checking no less than twenty times that the apple slices and peanut butter are in Tadashi's lunchbox, but never in Hiro's, because she does _not_ want him breaking out in hives on his first day of school. Or ever again, because that first time took ten years off her life, she _swears_. And for all that Hiro's a prodigy, he is utterly convinced that if there isn't a fruit rollup in his lunchbox, his day is fated to be awful.

The boys are at the table, and Tadashi seems utterly absorbed in what he's reading, but when Hiro filches his cup of coffee, Tadashi reaches over and plucks it out of his hands without so much as looking up. The eight year old huffs. "How come _you_ get to have coffee and I have to have orange juice?"

"Because _you_ weren't up late last night. And you like orange juice." Tadashi replies mildly.

"But it's not _fair!_"

"You'll be okay, Bonehead. Quit complaining and eat. We have to leave in a few minutes." Cass stares at him, because this is positively _cheerful_ for Tadashi. Over the years, she's gotten to know her nephews' habits very well. Hiro bounds out of bed in the morning, dresses with the kind of energy she can't hope to match, and comes downstairs already starving.

Tadashi is not a morning person. He usually makes his way downstairs a few minutes after Hiro does, goes straight for the coffee (were thirteen year olds even supposed to _drink_ coffee?) and he _might_ have a slice of toast or a bagel. Maybe. He reads as Hiro eats, and Hiro talks as he eats, and if Tadashi speaks, it's only to make threats to Hiro's physical well-being that no one takes seriously. For the elder Hamada brother to speak more than ten words in the morning is a rarity. Clearly, Hiro notices too. "What's got you in such a good mood?"

Tadashi's words make her freeze. "I'm a genius too."

She watches Hiro, worried. Tadashi had always been comparing himself to his younger brother and finding himself coming up short. If Hiro made the same comparison... he hadn't exactly learned tact yet, and this revelation of Tadashi's was so new, so fragile. Hiro snorts, and she starts trying to pull her 'stern parental figure' persona together, preparing for damage control. "You didn't _know_? I thought it was obvious."

Hiro goes for Tadashi's coffee again, and his brother takes it back and drains the cup before the third time can be a charm. He looks up though, quizzically, when Cass pulls Hiro bodily from his chair and crushes him in a tight hug. Hiro's grabbing for his bag the second she sets him down. "Come on, Dashi. We need to go."

She forces their lunches into her hands and holds the door open for them. Hiro is excited, rushed, and Tadashi reaches out in a lightning fast movement as he reaches the curb, seizing him by his hood and pulling him up short. "What's rule number 239?"

"Don't get Tadashi run over by a car." Hiro says sullenly.

"Or?" Tadashi prompts.

She hears Hiro's reply as the door swings shut. "Or a trolley." She flips the sign on the door to 'Open' and tries not to think about them getting run over by cars – or trolleys – and instead thinks about how proud she is of her two geniuses. She thinks about telling them, but Tadashi turns around when they reach the other side of the street and waves to her, and Hiro grins in her direction and grabs his brother's sleeve, tugging him along, and she's pretty sure they already know.


	6. Reaction

**Author's Note: Short chapter, all fluff. As always, a huge thanks to my readers. 3 you guys. **

Hiro could always tell when Tadashi had an idea that really excited him by his notebook. Most of the time, Tadashi's notes were neat and orderly, but sometimes, a project was so interesting that his small, precise handwriting was scratched out, written over, and interspersed with concept sketches that were little more than glorified stick figures. Hiro, though, was imaginative, and he could usually picture the finished result. These were the projects that he got involved in, and between the two of them and a lot of modifications, the end result was generally something truly impressive.

The volcano was made out of a titanium skeleton, and they had been forced to use a compressor to bend the solar panels into the right shape and weld them to the skeleton. Once that was done, they had fused a glass pump to house the lava, and connected it to a motor that was wired into the solar panels and could be remote activated by a controller Tadashi had re-purposed for the project. The two of them stood back, admiring their work. "I think I'm gonna get an A." Tadashi said finally. Hiro snorted.

"You think? This thing's so awesome, they'll have to invent a new grade. And you haven't even seen the lava yet?"

"Alright, Genius. Impress me." Tadashi challenged. Hiro grinned an dragged him to the sample he had set aside. The lava was bubbling sluggishly, glowing faintly, and steam rose from it in little wisps. Behind them, the volcano groaned with a faint, metallic sound. "Maybe I should reinforce the joints holding the panels on..."

"Maybe you should stop overthinking things and tell me how great I am."

"I have to hand it to you. This is impressive. How did you get the color? It's perfect."

"Easy, I synthesized chromium trioxide."

The volcano groaned again. "... And the glow?" Tadashi asked.

"Phosphorus."

Hiro heard Tadashi use a word that Aunt Cass only used when she thought they couldn't hear her, and then he was unceremoniously pulled into a bear hug. "Dashi?" There was a violent _snap_ and Tadashi's body lurched forward, then collapsed bonelessly. Hiro tried to catch him, but he wasn't strong enough to do much more than slow his brother's fall. "Tadashi! Tadashi wake up! … Tadashi?"

Tadashi was concussed, and had acquired several chemical burns from cleaning up their failed experiment. According to the doctor, it must have been very painful, but the eleven year old sat calmly while they applied and ointment and bandaged the burns. The hospital staff hypothesized that it was because of the concussion. Cass saw the tension in his jaw and in the line of his shoulders, but she also saw the way his gaze never left Hiro, and she knew better. Hiro had been too young to remember the accident, and he only barely remembered his parents, but it was clear that he had developed a dislike for hospitals that he would likely have for the rest of his life.

He was sitting on the edge of his chair, his fingers curled into fists, staring at his shoes, _clearly_ uncomfortable. So Tadashi was being strong – never whining or flinching- because to do so would only make this harder for Hiro, which was something the elder Hamada brother would never allow. Once the last bandage was in place, he stood, swaying on his feet, and smiled brightly. "Thanks for your help!"

Cass signed the discharge papers while keeping one eye on the two boys. Hiro was standing there, focused on his shoes, and Tadashi reached out and grabbed his little brother's hand, wincing. He said something that was too quiet for her to hear, and Hiro looked at him and _grinned_ and Cass resolved to ban them from conducting any more experiments for at least a month. She lectured them the entire way home, and she though Hiro might have been listening. Tadashi fell asleep, leaning against the door with his head resting against the window. Poor kid was going to have the mother of all headaches for _a while_.

She put him on the couch where she could keep an eye on him when they got home, and Hiro surprised her by sitting on the floor, leaned against the couch, and opening a book. It didn't take her long to realize that Hiro wanted to keep an eye on his brother too.

Tadashi was going to _kill_ his brother, who woke him up by tapping him in the center of the forehead. "_What_, Hiro?" He snarled, or at least, tried to snarl. It came out more as a whine.

"You're not supposed to sleep for more than four hours or you might never wake up." Hiro said seriously.

Tadashi opened his eyes to glare at his brother. "That's a _myth,_ now leave me alone!" He closed his eyes again.

"I'm sorry." Hiro said in a small voice. "I didn't mean to get you hurt Dashi. Rule # 121: We always check first to see what chemicals react badly with each other."

"Deal. Now come here." Tadashi pressed himself back into the cushions, and Hiro climbed onto the couch and snuggled up to his brother's warmth.

Cass found them twenty minutes later, asleep on the couch, with Hiro cuddled up against his brother's chest, and Tadashi's arm draped over Hiro's thin shoulders, and she couldn't resist taking a picture.


End file.
